Jeremy Corbyn is pledging to stand up for "exploited, ripped off and dehumanised workers", under plans dubbed a "game-changer" by unions.
The Labour leader is committing to take on Britain's "bad bosses" with what he believes is the biggest expansion of workers’ rights in Britain’s history as the party unveils its work manifesto.
The party claimed Amazon, Sports Direct, outsourcing giant ISS, Asda and Uber are among those with the worst records – but most of the companies quickly hit back.
Labour went on the offensive as Mr Corbyn met cleaners and catering staff who have organised themselves against employers in London on Tuesday.
The party is pledging a £10 minimum wage for all workers, a ban on zero-hours contracts and a requirement that all mid-shift breaks are paid.
Though the commitments have already been announced, Labour was highlighting them as part of its work manifesto.
Labour would also ban "bogus" self-employment, so bosses cannot evade workers’ rights, and repeal anti-trade union legislation, if it wins the December 12 election.
Mr Corbyn said: "The Conservatives are on the side of bad bosses who have exploited, ripped off and dehumanised workers.
"We’ll call time on insecure and unsafe work that leaves people without the rights and dignity they deserve. We’ll call time on discrimination in the workplace that leaves women vulnerable to harassment and unequal pay.
"And we’ll call time on the running down of workers’ rights to organise collectively to boost their pay and improve their working conditions."
The TUC union dubbed the plans a "game-changer".
Companies which Labour said would be affected by the crackdown have defended their records.
Uber said "drivers are at the heart of our service" - just weeks after it was banned in London over safety concerns.
Amazon said it "a safe, modern work environment", despite Labour's claims it treated staff in "appalling conditions".
Asda “entirely” rejected Labour’s allegations that the supermarket giant’s flexible contracts mean workers are not paid for breaks and are forced to work weekends and bank holidays, saying staff received pay rises for agreeing to the contracts.